These seeds were sowed when cities cashed in on commercial real estate, pushing residential zoning further and further out of the city. Wake up call: nobody wants to spend longer than they have to on an unpaid, unpredictable commute into the city anymore. So while these downtown businesses are getting 1/3 of the foot traffic that they used to, all the supermarkets and shops a few miles down the road are raking it in.
Right. The value has not been lost. It has been shifted. It happens.
Let's say you work from home and make your lunch. Previously you'd buy ready-to-eat lunch. While you still buy ingredients and pay for energy, you don't pay for someone to prepare it and then sell to you, prepare the housing of the eatery and so on. Effectively some GDP was lost. Next, let's say you grow some of your own veggies...